Irie T, Matsumura H, Terauchi R, Saitoh H
Department of Environmental Science, University of Shiga Prefecture, 2500 Hassaka-cho, Hikone, Shiga 522-8533, Japan.
Mol Genet Genomics. 2003 Nov;270(2):181-9. doi: 10.1007/s00438-003-0911-6. Epub 2003 Aug 29.
Treatment with cyclic AMP (cAMP) induces appressorium formation in the phytopathogenic fungus Magnaporthe grisea, the causative agent of rice blast disease. In a search for the M. grisea genes responsible for appressorium formation and host invasion, SAGE (Serial Analysis of Gene Expression) was carried out using mRNA isolated from fungal conidia germinating in the presence and absence of cAMP. From cAMP-treated conidia 5087 tags including 2889 unique tags were isolated, whereas untreated conidia yielded 2342 unique tags out of total of 3938. cAMP treatment resulted in up- and down-regulation of genes corresponding to 57 and 53 unique tags, respectively. Upon consultation of EST/cDNA databases, 22 tags with higher representation in cAMP-treated conidia were annotated with putative gene names. Furthermore, 28 tags corresponding to cAMP-induced genes could be annotated with the help of the recently published genome sequence of M. grisea. cAMP-induced genes identified by SAGE included many genes that have not been described so far, as well as a number of genes known to be involved in pathogenicity, e.g. MPG1, MAS1 and MAC1. RT-PCR of 13 randomly selected genes confirmed the SAGE results, verifying the fidelity of the SAGE data.
用环磷酸腺苷（cAMP）处理可诱导植物致病真菌稻瘟病菌（Magnaporthe grisea）形成附着胞，稻瘟病菌是稻瘟病的病原体。为了寻找负责附着胞形成和侵染宿主的稻瘟病菌基因，利用从在有或无cAMP情况下萌发的真菌分生孢子中分离的mRNA进行了基因表达系列分析（SAGE）。从经cAMP处理的分生孢子中分离出5087个标签，其中包括2889个独特标签，而未经处理的分生孢子在总共3938个标签中产生了2342个独特标签。cAMP处理分别导致对应于57个和53个独特标签的基因上调和下调。在查阅EST/cDNA数据库后，22个在经cAMP处理的分生孢子中具有较高代表性的标签被标注了假定的基因名称。此外，借助最近公布的稻瘟病菌基因组序列，可以标注28个对应于cAMP诱导基因的标签。通过SAGE鉴定的cAMP诱导基因包括许多迄今尚未描述的基因，以及一些已知参与致病性的基因，例如MPG1、MAS1和MAC1。对13个随机选择的基因进行的逆转录聚合酶链反应（RT-PCR）证实了SAGE结果，验证了SAGE数据的准确性。
